1. Field of the Invention
The invention relates to an apparatus for enhancing the environmental quality of work and living spaces. The apparatus combines a high efficiency particulate air filter, a means for moving air and a means for sound masking.
2. Information Disclosure
In recent years, growing attention has been focused on the impact of affective states on both interpersonal behavior and cognitive processes. With respect to interpersonal behavior, it has been found that individuals are generally more benevolent toward others (e.g., less aggressive, more helpful) when experiencing positive affect than when in a neutral mood or when experiencing negative affect. With respect to cognitive processes, it appears that even relatively mild shifts in current affect can influence both the encoding and retrieval of a wide range of information. Individuals experiencing positive affect seem to organize information differently--perhaps more inclusively--than persons not experiencing such reactions. They provide more unusual associates to neutral words and perceive nontypical exemplars of a category as more representative of that category than subjects in whom positive affect has not been induced. Persons experiencing positive affect are more likely to demonstrate risk-prone behavior when potential losses are small, but more likely to demonstrate risk-avoidance when potential losses are large. Finally, individuals experiencing positive affect perform more effectively on certain tasks (one involving creative problem solving) than do controls.
As information on the behavioral and cognitive impact of affective states has accumulated, many efforts have been made to apply such knowledge to behavior in applied settings. A number of recent studies have investigated the impact of affective states upon various aspects of work-related behavior. Together, this research suggests that relatively mild shifts in affective states can exert appreciable effects on behavior in work settings. Finally, recent evidence suggests that positive affect may enhance performance on difficult tasks, especially ones requiring creativity.
Such research indicates that both positive and negative affect can be readily generated by environmental conditions. Stressors such as excessive heat, irritating noise, or unpleasant aromas generate substantial levels of negative affect. Correspondingly, several environmental factors appear to produce positive affective states, including certain kinds of music or sounds, pleasant climatic conditions, and pleasant scents or the absence of unpleasant scents. Mold, pollen, animal dander, dust and bacterial spores may reasonably be expected to induce negative affect when circulated in the air. High efficiency particulate air (HEPA) filters provide the means for removing 99.9% of particulate matter from air, but because such filters are extremely dense (they remove particles as small as 0.3 microns), they require powerful transfer blower air systems to move air through their compact network of fibers. The resulting apparatus suffers from the drawback that any known means of moving a significant volume of air generates noise roughly proportional to the volume of air being moved and filtered. The current ASHRAE standards for offices and homes require 5 to 12 minutes per air change or 66 to 160 cfm for an 8.times.10.times.10 room. Since noise, particularly the high-frequency noise of air-filtering machinery, is likely to act as a source of negative affect, [see Nagar and Pandey J. Appl. Social Psych. 17 147-157 (1987)] whatever positive contribution is made by removal of airborne irritants is likely to be vitiated by the noise. Although the noise problem could, in principle, be mitigated by removing the air moving machinery to a site remote from the work or living space, this is a measure that can be applied only in certain circumstances.
There is therefore a need for a portable air-moving and filtering apparatus that would filter a meaningful volume of air without bathing the work or living space in an irritating noise. The present invention combines the sound produced by the air filtering system with a deliberately created additional sound to produce a positive affect, pink noise, which effectively masks distracting noise from surrounding areas.